1. Field of the Invention
The disclosed embodiments relate to a medical device. More specifically, the disclosed embodiments relate to a guidewire.
2. Description of Related Art
A guidewire is a known example of a medical device that is used for medical treatment in a blood vessel, such as percutaneous transluminal coronary angioplasty. A guidewire is used to guide a device, such as a balloon or a stent, to a lesion.
For example, Japanese Unexamined Patent Application Publication No. 5-42225, International Publication No. 2010/078335, and U.S. Pat. No. 4,917,104 each describe a guidewire including a core shaft that includes a distal end portion and a proximal end portion and a coil that covers an outer periphery of the core shaft. The guidewire is configured so that a distal end portion (distal portion) of the guidewire can be bent in a predetermined direction. In general, a distal end portion of a core shaft corresponds to a distal portion of a guidewire, and a proximal end portion of the core shaft corresponds to a proximal portion of the guidewire. A distal portion of a guidewire is inserted into a human body, and a proximal portion of the guidewire is operated by an operator, such as a doctor.
To be specific, the guidewire described in Japanese Unexamined Patent Application Publication No. 5-42225 includes a core shaft including a distal end portion and a proximal end portion, an inner coil that covers an outer periphery of the distal end portion, an outer coil that covers an outer periphery of the inner coil, and a pull wire. One end of the pull wire is connected to a distal end of the outer coil and the other end of the pull wire extends to the proximal end portion of the core shaft, and the pull wire is configured so that an operator can pull the pull wire. With the guidewire described in Japanese Unexamined Patent Application Publication No. 5-42225, a distal portion of the guidewire, which has a linear shape, can be bent by pulling the pull wire in the proximal direction.
Each of the guidewires described in International Publication No. 2010/078335 and U.S. Pat. No. 4,917,104 includes a core shaft that includes a distal end portion that has been bent beforehand and a coil that covers an outer periphery of the distal end portion of the core shaft along the bent shape of the distal end portion. A distal portion of the guidewire is bent in a predetermined direction.
U.S. Patent Application Publication No. 2005/0027212 describes a guidewire including a distal portion that is not bent and has a linear shape.